Question 1:   Find $\alpha$, if $\beta =56°$:

Question 2:   Find $\sphericalangle AOB$:

Question 3:   Find $AB$:

Question 4:   Find $\alpha$:

Question 5:   Find $\alpha$, where $\beta =43°$

Question 6:   Find $\measuredangle BEC$:

Question 7:   Find $\alpha$:

Question 8:   Find $\alpha$, if $\alpha =\beta$

Question 9:   Find the diameter $CD$:

Question 10:   Find the length of the chord $x$ in a circle with the radius $6cm$ if perpendicular distance from the chord to the circle center is $5cm$: